monopolist has too little incentive to carry out R&D aimed at displacing its own product. If the
patent holder is rational as is any other R&D investor, she will know that in equilibrium her
patent s obsolescence shall not be affected by her own R&D investment, because all the
R&D firms operate under perfect competition and constant returns to scale at the private
level. This reconciles Schumpeterian theory with the empirical evidence on innovation by …